The classic statement of the Mischief Rule is that given by the Barons of the Court of Exchequer in Heydon's Case (l584) 3 Co. Rep. 7a; 76 E.R. 637:
It was there laid down:
"that for the sure and true interpretation of all statutes in general (be they penal or beneficial, restrictive or enlarging of the common law) four things are to be discerned and considered:-
lst. What was the common law before the making of the Act.
2nd. What was the mischief and defect for which the common law did not provide.
3rd. What remedy the Parliament hath resolved and appointed to cure the disease of the Commonwealth.
And 4th. The true reason of the remedy; and then the office of all the Judges is always to make such construction as shall suppress the mischief, and advance the remedy, and to suppress subtle inventions and evasions for continuance of the mischief, and pro privato commodo, and to add force and life to the cure and remedy, according to the true intent of the makers of the Act, pro bono publico."
Later, in Coke's Institutes, we read to similar effect:
"Equity is a construction made by the judges, that cases out of the letter of a statute, yet being within the same mischief, or cause of the making of the same, shall be within the same remedy that the statute provideth; and the reason hereof is, for that the law-makers could not possibly set down all cases in express terms."
The approach in Heydon's case, emphasizing as it does the need to find the purpose or object or spirit of the statute and to advance that object in interpretation, nevertheless is expressed in the somewhat archaic language reflecting the view that statutes were a mere appendix to the common law. Today, the tables are reversed, and common law is increasingly being swallowed up by an orgy of legislation. Thus the modern rule in Heydon's case might be expressed better as to the first four points, this way:
1. What was the state of the law, if any, on the relevant subject matter before the legislation in question was passed?
2. What was the social, political, economic or other problem that gave rise to the need for the statute?
3. What was the solution that was to be embodied in the statute?
4. What was the purpose aimed at by this solution?
The mischief approach embodies a purposive interpretation of the text. Utilizing a much wider context for the text of the statute, we interpret the statute to advance the purpose. We all know that lawyers are "loophole hunters." The literal approach allows us to get around the purpose or spirit of the law by narrow construction. At other times, however, a plain reading may apply wider provisions of the statute to circumstances that arguably shouldn't be governed by the statute. The purposive approach would allow for a narrow reading of a wide provision, or a wider reading of a narrow provision, but only if the purpose of the statute demanded such a reading.